| Objective: Insulin resistance(IR)refers to a variety of reasons to promote glucose uptake and utilization of insulin decreased efficiency,compensatory hypersecretion of insulin produced hyperinsulinemia,to maintain the stability of blood sugar.Previous studies have shown that mitochondrial dysfunction may be the main cause of IR and related metabolic diseases,and exercise intervention can improve mitochondrial function.The silent information regulator 4(silence information negulator,Sirt4),which is located in the mitochondria,has been shown to be associated with insulin secretion.In order to further elucidate the mechanism of mitochondrial IR,exercise intervention clear effects of exercise on Sirt4,the IR of high-fat diet induced rat model of aerobic exercise,aerobic exercise on insulin resistance and Sirt4 after glutamate dehydrogenase and its substrate(glutamate dehydrogenase,GDH),insulin degrading enzyme(insulin-degrading,enzyme,IDE)adenine nucleotide transporter 2(adenine nucleotide translocator 2,ANT 2)linked expression in rat liver and insulin resistance.Methods: From 2-month-old Wistar rats,normal diet after 1 weeks of feeding were randomly divided into normal(basic diet: fat,protein and carbohydrate caloric contents were 10%,21%,69%,n=20)group and modeling(high fat diet: fat,protein and carbohydrate caloric contents were59%,20%,21%.N=20)group,model 5 weeks of feeding.The IR rats were randomly divided into high fat quiet group(IR)and high fat exercise group(IRe).The rats in the normal group were randomly divided into N group and normal exercise group(Ne).After second weeks of training,the wheel was used to carry out the rotation of the runner with a load of Bedford for about L weeks.6 weeks after the end of the training of hyperinsulinemic euglycemic clamp experiment model,rat femoral artery for determination of related biochemical indicators such as blood triglyceride,cholesterol,to measure the expression of Sirt4 and its substrates in liver by immunoblotting;using two factor analysis method on expression of Sirt4 and its substrates,IDE,GDHthe amount of ANT2 analysis.Results:(1)High fat diet induced IR in rats.The movement after the end of the period,compared with the N group,Ne group significantly decreased body weight(P<0.01),the weight of IRe rats was significantly lower than N group(P<0.05);compared with the IR group,IRe group rats were significantly lower(P<0.01).Compared with N group,the Ins of Ne group,IR group and IRe group were significantly higher(P<0.01).Compared with IR group,the Ins of rats in group IRe was significantly higher(P<0.05).IR in group TG was significantly higher than that in group N(P<0.05).The CHOL in the IR group was significantly higher than that in the N group(P<0.05).(2)Analysis of liver protein expression in rats show that,compared with the N group,Ne group,IR group of Sirt4 protein significantly decreased(P<0.05),and IRe in Sirt4 group compared with N group decreased significantly(P<0.01);compared with IR group,the expression of IRe protein in Sirt4 group decreased obviously(P<0.05).Compared with IR group,the expression of GDH protein in Ne group and IRe group was significantly higher(P<0.05).The expression of IDE protein in IR group was significantly higher than that in N group(P<0.05).Compared with IR group,the expression of IDE was significantly lower in IRe group(P<0.05).Conclusion:(1)Aerobic exercise can improve the IR rats’ physiological and biochemical indexes to some extent,and improve the state of IR.(2)IR and aerobic exercise can induce the decrease of Sirt4 protein expression in rats,which may involve different mechanisms.Aerobic exercise can lead to reverse changes of Sirt4 substrate IDE and GDH in the liver of IR rats,which may be one of the mechanisms of aerobic exercise to improve IR in rats. |
